Expanding tropics?

[displaced_floridian]

Hurricanes and typhoons at their peak intensities are shifting away from the equator and towards the poles, scientists reported Wednesday, potentially placing coastal areas that are unaccustomed to deadly storms in their path if the trend continues.

Satellite data going back to 1980 show a global average shift of about 35 miles each decade on both sides of the equator, the experts announced in the peer-reviewed journal Nature.

This “pronounced poleward migration” means “potentially profound consequences for life and property” if the trend continues, according to the scientists from the National Oceanic and Atmospheric Administration and the Massachusetts Institute of Technology.

The poleward migration follows earlier studies showing an expansion during the same time period of the tropics, the area along the equator defined by warm, humid weather.

The tropics’ expansion has been linked to manmade problems: ozone depletion, air pollution and greenhouse gases tied to global warming, Kossin noted. But figuring out to what extent each plays a role is needed before finding a fix.

Here's the link: http://www.nbcnews.com/science/environment/hurricanes-are-shifting-putting-new-areas-danger-study-says-n105371

[SubTropicRay]

Interesting stuff. The tropics won't make it here in my lifetime. Miami's current climate eventually in Tampa? That's a real possibility before I die.

[Palmaceae]

I would like Key West's climate this weekend!

[tropicbreeze]

Hidden in the details of that article:

"There is an interesting caveat: A shift was not seen in the North Atlantic."

[Moose]

Oh boy - 70 miles in twenty years, That would put my garden in Zone 11. Then I can plant all those Seychelles palms that I lost when I got cocky back in 2007. Too bad I'll have to wait until I'm 75

[Silas_Sancona]

Have seen the same report and see some truth behind the thought. Also saw another article related to the potential of much milder winters by the turn of the century. Believe it was published by the same people who did a report regarding how much hotter X city might be 100 years from now.

Was interesting to see that, for example, say Tucson averages 15 days where winter lows may drop below 32F.. and how it may happen that Tucson sees less than 5 days during the winter where temps below 32F might be expected by 2099. Hence winters in Tucson becoming more like Brownsville Texas, or so was theorized in the article.

If indeed the tropical belts are expanding, Animals will always be the first to explore newer areas and the increasingly common occurrence of any particular species now considered rarely sighted or one which occasionally visits could serve as a valuable indicator of expanding warmth. Birds in particular.

As far as tropical systems are concerned, under warmer/more humid conditions, do believe California will experience one in my lifetime.. as warmer waters and other factors allow more systems to survive the trip north up Baja. I also think the occurrence of the Southwestern Monsoonal cycle will become more widespread and pronounced both in Arizona and in CA. as well as the "target" area in Sonora Mexico shifts north. Just my 2 cents.

-Nathan

[Zeeth]

I think I agree with the sentiment that Florida hasn't changed much. Check out this chart of the mean January temp for Sarasota from 1950 to 2015. There's a tiny downward trend more than anything.

[palmsOrl]

Miami's climate is tropical, just barely and when I'm there I can tell. Outside of urban areas (which are obviously warmer for straight forward reasons) I don't think the climate of FL is getting warmer. With climate change, some areas are predicted to actually get colder and some areas may actually have very little, if any change. This is just my opinion though.

[Kailua_Krish]

I know this isn't very scientific but I was speaking with one of my older family members (93 years old) and she says that she remembers the nights in Florida getting a lot cooler when she was younger, particularly during the fall/winter months. Cold enough they would routinely use fires in a fireplace. She is from out in the woods around Alachua/Levy county. I wonder if this is more a product of urban heat trapping than climate change though.

[palmsOrl]

As a child, I lived in Gainesville for a couple years while my mom went to law school. The winter nights there were MUCH chillier on average than Orlando and this would often start in late October and last as late as April. We stocked up on fire wood and had a fire many nights. I would see heavy frost on the fields up there quite often from A December to February. It was almost like having truly four seasons.

[Zeeth]

I think I agree with the sentiment that Florida hasn't changed much. Check out this chart of the mean January temp for Sarasota from 1950 to 2015. There's a tiny downward trend more than anything.

I was curious how this downward trend was reflected in the zone, so I did a graph of that as well. Interestingly, there is a slight upward trend of that. I'm not sure how to interpret this data, but here is is.

[Dakotafl]

I don't know much about Climate Change, but the Earth isn't static either, of course change will gradually come and a few degrees warmer or cooler isn't a stretch.

I know Melbourne, Fl must have been similar as it is now in the 50s, since I have seen pics of 30 ft Coconut palms in an area history book...some areas are also warmer without Urban buildup, for example, Valkaria is much warmer on the coldest nights than some built up areas of Palm Bay, and I don't mean just by the water.

Royal Palms existed naturally near lake George in Bartrams time, so maybe the zones will shift back...who knows, maybe we live in the abnormally cool time and normally it would be much warmer. hehe

Edited February 13, 2015 by Dakotafl

[Coconutman]

Amazing that some parts of St.pete/S.Tampa would look like Miami.

[Mr. Coconut Palm]

As someone mentioned above, the range of tropical animals expanding outside their normal range would probably indicate the tropics expanding. Here in Corpus Christi, there is actually a breeding population of green parakeets that are native to the Rio Grande Valley and southward into Central America. These are more like conures, since they are larger than the typical parakeets sold in pet shops. And this breeding population of them nests in the old Canary Island Date Palms at the retreat center on what used to be the old Catholic College many years ago, which is on the northwest side of town (a cooler area at night in the winter than here by the Laguna Madre and Gulf, but only about a block and a half from the port). Also, the last 3 years, at the jetties at Packery Channel (the channel that separates Padre Island from Mustang Island), there have been dozens of juvenile French Angelfish, which you Floridians know is a tropical reef fish. I have been snorkeling and scuba diving on Texas jetties for many years going back to when I was in high school 30 years ago, and even though we have lots of sergeant majors, a few Dusky Damsels, and hundreds of Mangrove Snappers, and a few Spotfin Butterflyfish, I have never seen any angelfish before. There are reports in books like "Fishes of the Gulf of Mexico, Texas, Louisiana and Adjacent Waters" of them occasionally occurring on our jetties in the summer, but I had never seen any until 3 years ago, and my wife and I counted at least 50 before we quit counting. Also, since then, I have noticed a few Cocoa Damsels too in their juvenile bright yellow and purple phase. We also notice in October of 2012, a large school of huge Snook about 4ft. long along the South Jetty of Packery Channel one afternoon while snorkeling there. Until recently, I had never seen a Snook on the Texas Coast, but I have heard reports that there used to be some along the South Texas Coast before the 1983 freeze.

Anyway, all this along with the fact that there are those of us trying to grow coconut palms here in Corpus Christ, with some degree of success, when this wouldn't have even been possible 30 years ago, makes me think that the tropics are indeed expanding. In my lifetime, I have literally seen Corpus Christi's climate change. In the '80's, most of Corpus was 9A, with only the immediate Bayfront, Flour Bluff (where I live), and North Padre Island being 9B (with the island being at the high end of 9B), but now according to the new USDA Climate Zone Map, most of Corpus to just past the airport is 9B, with only the far western parts of the city away from the water being the high end of 9A, and the east end of the immediate Bayfront, Flour Bluff, and North Padre Island being 10A (with the island being at the high end of 10A)! The Rio Grande Valley has gone in the same time frame from being 9A at the far western most inland part of the Valley at the high end of 9A, most of the Valley at 9B, and only Port Isabel and South Padre barely being 10A to the most western inland part of the Valley being solidly 9B, and the whole eastern part of the Valley from just east of McAllen eastward to being solidly 10A, to Port Isabel being borderline 10B, and South Padre being 10B!

[SubTropicRay]

There's been no February freeze in Tampa since 1996 (knock on wood). That streak is unprecedented. There have been 3 December freezes since 1989. For the most part, winter has been reduced to January. Forget climate change. How about local changes resulting from urbanization? I think some microclimates like this have never been warmer.

[Tropicdoc]

I got one thread telling me the tropics are creeping my way and another telling me global warming is causing more escape of arctic air to spread down here during winter. Ugh. I just wish my climate would stabilize at a nice predictable 9b.

[Dakotafl]

Aren't we forgetting that the climate in the medieval ages in Europe was warmer than it is today? Notice the experts dumped the term "Global Warming" and now say that the climate is just going to be more extreme than in the past, Cold or Hot and both, Hurricanes, Tornadoes, ect, this ignoring the fact that more severe events have been recorded regarding weather in the past than now.

[John Case]

Have seen the same report and see some truth behind the thought. Also saw another article related to the potential of much milder winters by the turn of the century. Believe it was published by the same people who did a report regarding how much hotter X city might be 100 years from now.

Was interesting to see that, for example, say Tucson averages 15 days where winter lows may drop below 32F.. and how it may happen that Tucson sees less than 5 days during the winter where temps below 32F might be expected by 2099. Hence winters in Tucson becoming more like Brownsville Texas, or so was theorized in the article.

If indeed the tropical belts are expanding, Animals will always be the first to explore newer areas and the increasingly common occurrence of any particular species now considered rarely sighted or one which occasionally visits could serve as a valuable indicator of expanding warmth. Birds in particular.

As far as tropical systems are concerned, under warmer/more humid conditions, do believe California will experience one in my lifetime.. as warmer waters and other factors allow more systems to survive the trip north up Baja. I also think the occurrence of the Southwestern Monsoonal cycle will become more widespread and pronounced both in Arizona and in CA. as well as the "target" area in Sonora Mexico shifts north. Just my 2 cents.

-Nathan

We could use a little Mexican monsoon weather around here!

[tropicbreeze]

Aren't we forgetting that the climate in the medieval ages in Europe was warmer than it is today? Notice the experts dumped the term "Global Warming" and now say that the climate is just going to be more extreme than in the past, Cold or Hot and both, Hurricanes, Tornadoes, ect, this ignoring the fact that more severe events have been recorded regarding weather in the past than now.

In the medieval times there used to be markets on the frozen River Thames and it was used as a thoroughfare by wheeled traffic. Hasn't happened now in a long time. In Holland skating along frozen canals was a common mode of transport in times gone by, now a rare event. Hardly an indication of it being warmer back then.

If there is expansion of the tropics the effects on wildlife won't just be tropical animals moving into newly benign habitat, it'll also be temperate wildlife withdrawing from newly hostile habitat.

[Silas_Sancona]

Mr. Coconut Palm..

Interesting observations.. I think South Texas would be one of the best places for observing/ recording various animal species moving north out of Continental Mexico. Unlike trying to get to Florida, there isn't a large body of water to cross to relocate to potentially suitable new homes. Even if the records are older, I'm amazed at how many species of "tropical" Butterflies or Hummingbirds have been recorded straying into/ regularly visiting areas around Brownsville.. as a pose to say South Florida.

Tropicbreeze..

Very True, and wouldn't doubt that may be happening, or will.

John (Bepah)

Have theorized about this since I was a kid.. and after looking over old text books regarding past climate in CA and the Southwest.

When you look at a warmer-climate scenario, I can see how the precip. patterns in CA may change quite a bit. (Deflected Jet Stream/ persistent blocking High Pressure/ more rain than snow in the Mountains). On the other hand, say over time, average SSTs off Santa Cruz average 64-70F in July and maybe reach the low 80's south of Pt. Conception more often due to less upwelling and a weaker CA. Current allowing warmer water to migrate further north out of Baja.

Warmer temps off CA + an even warmer Gulf of CA would translate into more moisture being present in the Atmosphere. Add in an expanded/stronger Monsoonal set up and less chance the usual northwesterly flow would push it out/ keep the local Atmosphere stabilized and the idea of more quick, heavy rain events in the summer, especially the further south/inland you go seems more likely. Also, less marine influence would allow the land mass to warm more, further enabling convective summer storms.

Atm, It is all theory and only time will tell but if the idea is " expanding northward " it isn't hard to see weather patterns and animals doing the same. Jaguars in L.A. anyone?

-Nathan

[Sandy Loam]

Although those arctic pushes of cold air into the south seem to have worsened as climate change increases, there are nonetheless black mangroves growing along the Gulf of Mexico coast at least as far north as Cedar Key, Florida and even Shired Island, Florida. Those mangroves trees are still tiny and juvenile, but I am told that they didn't used to grow there at all because the region was simply farther north than mangrove trees' native habitat (I suppose the mangrove line used to be drawn somewhere around Tampa Bay)

[displaced_floridian]

I have been interested in weather since I was a little kid, and still have a book called simply "Weather". It was published in the late 50s. It was written for about a 10-year old. One thing I noticed when rereading it recently was, when describing lake-effect snows in the Great Lakes, it said they can be particularly heavy, especially BEFORE THEY ARE FROZEN, as if it was normal for them to completely freeze over every winter. Now, when the partially freeze, it's big news.

[Mr. Coconut Palm]

There are thousands of black mangroves along the Texas Coast at least as far north as Galveston, where I have seen some 4.5 to 5ft. tall. Here in the Corpus Christi area, we have a few that are in the 8 to 12ft. tall range and there are entire mangrove swamps of them by the tens of thousands around Port Isabel and South Padre Island. I have even seen two red mangroves, one about 7ft. tall and the other about 4ft. tall, both loaded with viable seeds hanging down in a black mangrove tidal creek at Boca Chica at the Rio Grande Delta back in 2007. The black mangrove is subtropical, whereas the red mangrove is tropical. I have read a report of a small colony of red mangroves growing on the Texas coast as far north as the back side of Matagorda Island along Matagorda Bay, but have been unable to verify this since you can only get there by boat. There are some areas along the southern Louisiana coast that have a lot of black mangroves, and the Chadeleur Islands off the east Coast of the Mississippi Delta used to be basically mangrove island made up of many black mangroves (and possibly a few small red mangroves?) before Hurricane Katrina devastated these low lying islands, then the BP oil spill pretty much ruined what was left of these islands.

[Jimbean]

climate is a matter of physics. In order to get a better prediction of where the climate is heading, you need:

1.) as much accurate historical information as possible

2.) an understanding of all endogenous factors

3.) an understanding of all exogenous factors (the sun being the biggest).

4.) calculate the several probablities

From my understanding, climate change is like tides of an ocean. Habitats have sort of seesawed back and forth for millennia. I think there was once ancient saw palmettos in South Dakota and coral reef beds in what is now Yellowstone. During the last Ice age, there were boreal forests in the Carolinas.

[_Keith]

climate is a matter of physics. In order to get a better prediction of where the climate is heading, you need:

1.) as much accurate historical information as possible

2.) an understanding of all endogenous factors

3.) an understanding of all exogenous factors (the sun being the biggest).

4.) calculate the several probablities

From my understanding, climate change is like tides of an ocean. Habitats have sort of seesawed back and forth for millennia. I think there was once ancient saw palmettos in South Dakota and coral reef beds in what is now Yellowstone. During the last Ice age, there were boreal forests in the Carolinas.

Nah, I am pretty sure that all of the people in China and India have enough weight that they have tilted the rotational axis of the planet. That's the real cause for all of this.

[amazondk]

I think you may be right Keith. Anyway it has not gotten any cooler here on the equator. Well during the last ice age it was about 10 degrees F cooler on a yearly average. But, that still would mean that the coldest temperature during the year was about 60 F. I have not noticed any wolverines around here at all. There are quite a few jaguars though. I have not noticed it getting any hotter either.

dk

[amazondk]

Aren't we forgetting that the climate in the medieval ages in Europe was warmer than it is today? Notice the experts dumped the term "Global Warming" and now say that the climate is just going to be more extreme than in the past, Cold or Hot and both, Hurricanes, Tornadoes, ect, this ignoring the fact that more severe events have been recorded regarding weather in the past than now.

In the medieval times there used to be markets on the frozen River Thames and it was used as a thoroughfare by wheeled traffic. Hasn't happened now in a long time. In Holland skating along frozen canals was a common mode of transport in times gone by, now a rare event. Hardly an indication of it being warmer back then.

If there is expansion of the tropics the effects on wildlife won't just be tropical animals moving into newly benign habitat, it'll also be temperate wildlife withdrawing from newly hostile habitat.

I believe it was warmer before this time. That was the mini ice age.

[tropicbreeze]

I believe it was warmer before this time. That was the mini ice age.

Or was that earlier warmer period just a 'mini interglacial'?